Worn valves, valve guides, and/or valve stem oil seals

1. Inspect the spark plugs for oil deposits. Refer to Spark Plug Inspection .
2. Repair or replace, as required.

Worn piston rings

Oil consumption may or may not cause the engine to misfire.

1. Inspect the spark plugs for oil deposits. Refer to Spark Plug Inspection .
2. Inspect the cylinders for a loss of compression. Refer to Engine Compression Test .
3. Perform cylinder leak down and compression testing to determine the cause. Refer to Cylinder Leakage Test .
4. Repair or replace, as required.